Triple Monitor Mount Triple Monitor Setup?

Triple monitor setup? - triple monitor mount

Hello boys
I have a HD 4870 now and is not compatible with 3 LCD screens. I'm getting another 24 "and are mounted on an LCD arm, so I planned to go and get a HD 5570, but this only works if you use the port for a screen and no monitors.
My other option is to a lesser degree of supervision Nvidia only 3 I do not believe that the proliferation of images in all three TriBox wow, that everyone has the images obtained separately.
Just need to know if I can, the HD 5770, without having to buy a converter from DP or if I use a low degree of Nivida card. I am using Windows 7 64-bit.

Regards
Nathan